The parent is not wrong:
The total number of children in the world has already peaked (2017?) and is now dropping.
The population growth should still continue for about a human lifespan from here (50-80 years depending on who you ask).
That last growth is just those children growing up and becoming adults. I.e. They are the “last big generation”.
We will see the population drop again, if we dont fuck up the planet before that happens.
I think you would have difficulty finding countries in the world where fertility rates (children born pr woman) are not dropping.
Bangladesh went from 5.5 kids pr woman in 1985 to 2.1 in 2017. This is a global trend.